In the past, in a turbo refrigerator, heat transport has been performed by circulating a refrigerant between a condenser and an evaporator, condensing the refrigerant compressed in a turbo compressor, in the condenser, and evaporating the condensed refrigerant in the evaporator.
In order to efficiently vaporize the refrigerant in the evaporator, it is desirable that there is less of a gas-phase component which is contained in the refrigerant which is supplied to the evaporator. For this reason, as shown in, for example, Patent Document 1, an economizer is installed ahead of an evaporator, and thus a gas-phase component of a refrigerant which is supplied to the economizer is removed, and the removed gas-phase component of the refrigerant is returned to a turbo compressor.
Patent Document 2 and Patent Document 3 disclose the detailed configuration of a site where in Patent Document 1, the removed gas-phase component of the refrigerant is returned from the economizer to the turbo compressor.